cprover
boolbv_with.cpp
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1 /*******************************************************************\
2 
3 Module:
4 
5 Author: Daniel Kroening, kroening@kroening.com
6 
7 \*******************************************************************/
8 
9 #include "boolbv.h"
10 
11 #include <util/arith_tools.h>
12 #include <util/c_types.h>
13 #include <util/namespace.h>
14 #include <util/std_expr.h>
15 
17 {
18  bvt bv = convert_bv(expr.old());
19 
20  std::size_t width=boolbv_width(expr.type());
21 
22  if(width==0)
23  {
24  // A zero-length array is acceptable:
25  if(
26  expr.type().id() == ID_array &&
28  {
29  return bvt();
30  }
31  else
32  return conversion_failed(expr);
33  }
34 
36  bv.size() == width,
37  "unexpected operand 0 width",
39 
40  bvt prev_bv;
41  prev_bv.resize(width);
42 
43  const exprt::operandst &ops=expr.operands();
44 
45  for(std::size_t op_no=1; op_no<ops.size(); op_no+=2)
46  {
47  bv.swap(prev_bv);
48 
49  convert_with(expr.old().type(), ops[op_no], ops[op_no + 1], prev_bv, bv);
50  }
51 
52  return bv;
53 }
54 
56  const typet &type,
57  const exprt &op1,
58  const exprt &op2,
59  const bvt &prev_bv,
60  bvt &next_bv)
61 {
62  // we only do that on arrays, bitvectors, structs, and unions
63 
64  next_bv.resize(prev_bv.size());
65 
66  if(type.id()==ID_array)
67  return convert_with_array(to_array_type(type), op1, op2, prev_bv, next_bv);
68  else if(type.id()==ID_bv ||
69  type.id()==ID_unsignedbv ||
70  type.id()==ID_signedbv)
71  return convert_with_bv(op1, op2, prev_bv, next_bv);
72  else if(type.id()==ID_struct)
73  return
74  convert_with_struct(to_struct_type(type), op1, op2, prev_bv, next_bv);
75  else if(type.id() == ID_struct_tag)
76  return convert_with(
77  ns.follow_tag(to_struct_tag_type(type)), op1, op2, prev_bv, next_bv);
78  else if(type.id()==ID_union)
79  return convert_with_union(to_union_type(type), op2, prev_bv, next_bv);
80  else if(type.id() == ID_union_tag)
81  return convert_with(
82  ns.follow_tag(to_union_tag_type(type)), op1, op2, prev_bv, next_bv);
83 
85  false, "unexpected with type", irep_pretty_diagnosticst{type});
86 }
87 
89  const array_typet &type,
90  const exprt &op1,
91  const exprt &op2,
92  const bvt &prev_bv,
93  bvt &next_bv)
94 {
95  // can't do this
97  !is_unbounded_array(type),
98  "convert_with_array called for unbounded array",
100 
101  const exprt &array_size=type.size();
102 
103  const auto size = numeric_cast<mp_integer>(array_size);
104 
106  size.has_value(),
107  "convert_with_array expects constant array size",
109 
110  const bvt &op2_bv=convert_bv(op2);
111 
113  *size * op2_bv.size() == prev_bv.size(),
114  "convert_with_array: unexpected operand 2 width",
116 
117  // Is the index a constant?
118  if(const auto op1_value = numeric_cast<mp_integer>(op1))
119  {
120  // Yes, it is!
121  next_bv=prev_bv;
122 
123  if(*op1_value >= 0 && *op1_value < *size) // bounds check
124  {
125  const std::size_t offset =
126  numeric_cast_v<std::size_t>(*op1_value * op2_bv.size());
127 
128  for(std::size_t j=0; j<op2_bv.size(); j++)
129  next_bv[offset+j]=op2_bv[j];
130  }
131 
132  return;
133  }
134 
135  typet counter_type=op1.type();
136 
137  for(mp_integer i=0; i<size; i=i+1)
138  {
139  exprt counter=from_integer(i, counter_type);
140 
141  literalt eq_lit=convert(equal_exprt(op1, counter));
142 
143  const std::size_t offset = numeric_cast_v<std::size_t>(i * op2_bv.size());
144 
145  for(std::size_t j=0; j<op2_bv.size(); j++)
146  next_bv[offset+j]=
147  prop.lselect(eq_lit, op2_bv[j], prev_bv[offset+j]);
148  }
149 }
150 
152  const exprt &op1,
153  const exprt &op2,
154  const bvt &prev_bv,
155  bvt &next_bv)
156 {
157  literalt l=convert(op2);
158 
159  if(const auto op1_value = numeric_cast<mp_integer>(op1))
160  {
161  next_bv=prev_bv;
162 
163  if(*op1_value < next_bv.size())
164  next_bv[numeric_cast_v<std::size_t>(*op1_value)] = l;
165 
166  return;
167  }
168 
169  typet counter_type=op1.type();
170 
171  for(std::size_t i=0; i<prev_bv.size(); i++)
172  {
173  exprt counter=from_integer(i, counter_type);
174 
175  literalt eq_lit=convert(equal_exprt(op1, counter));
176 
177  next_bv[i]=prop.lselect(eq_lit, l, prev_bv[i]);
178  }
179 }
180 
182  const struct_typet &type,
183  const exprt &op1,
184  const exprt &op2,
185  const bvt &prev_bv,
186  bvt &next_bv)
187 {
188  next_bv=prev_bv;
189 
190  const bvt &op2_bv=convert_bv(op2);
191 
192  const irep_idt &component_name=op1.get(ID_component_name);
193  const struct_typet::componentst &components=
194  type.components();
195 
196  std::size_t offset=0;
197 
198  for(const auto &c : components)
199  {
200  const typet &subtype = c.type();
201 
202  std::size_t sub_width=boolbv_width(subtype);
203 
204  if(c.get_name() == component_name)
205  {
207  subtype == op2.type(),
208  "with/struct: component '" + id2string(component_name) +
209  "' type does not match",
210  irep_pretty_diagnosticst{subtype},
212 
214  sub_width == op2_bv.size(),
215  "convert_with_struct: unexpected operand op2 width",
217 
218  for(std::size_t i=0; i<sub_width; i++)
219  next_bv[offset+i]=op2_bv[i];
220 
221  break; // done
222  }
223 
224  offset+=sub_width;
225  }
226 }
227 
229  const union_typet &type,
230  const exprt &op2,
231  const bvt &prev_bv,
232  bvt &next_bv)
233 {
234  next_bv=prev_bv;
235 
236  const bvt &op2_bv=convert_bv(op2);
237 
239  next_bv.size() >= op2_bv.size(),
240  "convert_with_union: unexpected operand op2 width",
242 
243  endianness_mapt map_u = endianness_map(type);
244  endianness_mapt map_op2 = endianness_map(op2.type());
245 
246  for(std::size_t i = 0; i < op2_bv.size(); i++)
247  next_bv[map_u.map_bit(i)] = op2_bv[map_op2.map_bit(i)];
248 }
constant_exprt from_integer(const mp_integer &int_value, const typet &type)
Definition: arith_tools.cpp:99
const union_tag_typet & to_union_tag_type(const typet &type)
Cast a typet to a union_tag_typet.
Definition: c_types.h:202
const union_typet & to_union_type(const typet &type)
Cast a typet to a union_typet.
Definition: c_types.h:162
Arrays with given size.
Definition: std_types.h:763
const typet & element_type() const
The type of the elements of the array.
Definition: std_types.h:777
const exprt & size() const
Definition: std_types.h:790
const namespacet & ns
Definition: arrays.h:56
virtual bvt convert_with(const with_exprt &expr)
Definition: boolbv_with.cpp:16
void convert_with_bv(const exprt &op1, const exprt &op2, const bvt &prev_bv, bvt &next_bv)
bool is_unbounded_array(const typet &type) const override
Definition: boolbv.cpp:547
virtual const bvt & convert_bv(const exprt &expr, const optionalt< std::size_t > expected_width=nullopt)
Convert expression to vector of literalts, using an internal cache to speed up conversion if availabl...
Definition: boolbv.cpp:40
void convert_with_struct(const struct_typet &type, const exprt &op1, const exprt &op2, const bvt &prev_bv, bvt &next_bv)
void convert_with_union(const union_typet &type, const exprt &op2, const bvt &prev_bv, bvt &next_bv)
bvt conversion_failed(const exprt &expr)
Print that the expression of x has failed conversion, then return a vector of x's width.
Definition: boolbv.cpp:84
virtual endianness_mapt endianness_map(const typet &type, bool little_endian) const
Definition: boolbv.h:105
virtual std::size_t boolbv_width(const typet &type) const
Definition: boolbv.h:99
void convert_with_array(const array_typet &type, const exprt &op1, const exprt &op2, const bvt &prev_bv, bvt &next_bv)
Definition: boolbv_with.cpp:88
dstringt has one field, an unsigned integer no which is an index into a static table of strings.
Definition: dstring.h:37
Maps a big-endian offset to a little-endian offset.
size_t map_bit(size_t bit) const
Equality.
Definition: std_expr.h:1225
Base class for all expressions.
Definition: expr.h:54
std::vector< exprt > operandst
Definition: expr.h:56
typet & type()
Return the type of the expression.
Definition: expr.h:82
operandst & operands()
Definition: expr.h:92
const irep_idt & get(const irep_idt &name) const
Definition: irep.cpp:45
const irep_idt & id() const
Definition: irep.h:396
const union_typet & follow_tag(const union_tag_typet &) const
Follow type tag of union type.
Definition: namespace.cpp:63
literalt convert(const exprt &expr) override
Convert a Boolean expression and return the corresponding literal.
virtual literalt lselect(literalt a, literalt b, literalt c)=0
Structure type, corresponds to C style structs.
Definition: std_types.h:231
const componentst & components() const
Definition: std_types.h:147
std::vector< componentt > componentst
Definition: std_types.h:140
The type of an expression, extends irept.
Definition: type.h:29
The union type.
Definition: c_types.h:125
Operator to update elements in structs and arrays.
Definition: std_expr.h:2312
exprt & old()
Definition: std_expr.h:2322
const std::string & id2string(const irep_idt &d)
Definition: irep.h:47
std::vector< literalt > bvt
Definition: literal.h:201
BigInt mp_integer
Definition: smt_terms.h:12
#define DATA_INVARIANT_WITH_DIAGNOSTICS(CONDITION, REASON,...)
Definition: invariant.h:511
API to expression classes.
const struct_typet & to_struct_type(const typet &type)
Cast a typet to a struct_typet.
Definition: std_types.h:308
const array_typet & to_array_type(const typet &type)
Cast a typet to an array_typet.
Definition: std_types.h:832
const struct_tag_typet & to_struct_tag_type(const typet &type)
Cast a typet to a struct_tag_typet.
Definition: std_types.h:474